The present invention relates generally to flatwork article feeding machines, and more particularly, to an apparatus and method for transferring a sheet of laundry from a loading station to a pickup station where the sheet is engageable by a moving mechanism.
In commercial laundry facilities, laundry articles such as bed sheets, table linens, blankets, or the like are typically fed into a flatwork ironer and automatic folder after they are washed. The flatwork ironer dries and irons the wet sheets and the automatic folder folds and cross-folds the sheets into a neat package for use in hotels, hospitals, or the like. In order to obtain a neatly folded, unwrinkled package, it is important that the sheet be presented to an ironer and/or folder with no wrinkles or folds and with the leading edge square. In the past, operators have been employed to manually spread the sheet apart and place it in the ironer by hand. However, the use of operators tends to slow the output of the ironer and can lead to inaccurate and inconsistent placement of the sheet in the ironer. In addition, accurate placement of the sheet depends on the skill of the operators, the operators can become fatigued, and utilizing multiple operators increases costs. To overcome this difficulty, modern laundry facilities use automatic spreader-feeder machines to allow more rapid and accurate feeding of the sheets into the ironer.
These spreader-feeder machines typically include a continuously moving feed conveyor on which the sheets are automatically laid with their leading edges perpendicular to the conveyor belts. In order to position the sheet for placement onto the conveyor, a pair of spreading clamps are typically employed to grip opposing top corners of the sheet. The spreading clamps are then moved apart by one or more endless belts or cables to spread the sheet in front of the conveyor. Once the sheet is spread to the desired position, the spreading clamps release the corners of the sheet and the upper portion of the sheet is forced onto the conveyor. The conveyor then advances the sheet to the ironer or other processing equipment. Various machines of this general type are disclosed in U.S. Pat. No. 4,106,227 to Allen et al. and U.S. Pat. Nos. 4,967,495, 4,345,391, 3,421,756, and 3,376,036 to Weir.
One disadvantage of many spreader-feeder machines is the time required for an operator to load the sheet. Typically, an operator has to pick up a loose sheet from a pile, locate one or two corner portions of the sheet, and manually clamp the corner portions to the spreading clamps. This time consuming task limits the speed at which the sheets can be loaded and fed to an ironer. To increase output, some spreader-feeder machines are designed to accommodate multiple operators at different loading stations. One way to provide multiple loading stations is to include a plurality of sets of spreading clamps as disclosed in the '227 patent to Allen et al. Another way is to provide a transfer mechanism which transfers the sheets from multiple loading stations to a single pair of spreading clamps. For example, the machine disclosed in the '036 patent to Weir includes clips mounted on arms which swing laterally from an outer position to a center position where the spreading clamps pick up the sheet. In these types of machines, however, the operators still have to locate the corner portions of the sheet for insertion into a pair of clamps. Although these machines increase output, their efficiency is still dependent on the manipulation of the sheets by one or more operators. Thus, it is desirable to provide a spreader-feeder machine which increases the speed at which a sheet can be loaded by eliminating the need to precisely manipulate the sheets. More particularly, it is desirable to provide a machine which obviates the need for an operator to locate and manually clamp a corner portion of a sheet.
Attempts have been made to provide a spreader-feeder machine which does not require an operator to locate and manually clamp the corner portions of a sheet. For example, U.S. Pat. Nos. 4,031,639 and 3,464,131 to McCabe et al. disclose spreader-feeder mechanisms including a plurality of spreader belts which diverge to spread the sheet for placement on the feed conveyor. To load the sheet, an operator locates the leading edge of the sheet and places a center portion on the spreader belts. One disadvantage of this type of machine is the difficulty in keeping the leading edge of the sheet square with the feed conveyor. If the center portion of the sheet is not laid properly on the spreader belts, the sheet tends to spread unevenly. Moreover, additional operators may be required to be correct unevenly spread sheets. Other machines utilizing diverging belts to spread the sheet without clamps are disclosed in U.S. Pat. Nos. 3,772,808 to Behn and 3,807,068 to Ross. Yet another type of laundry feeder machine is disclosed in U.S. Pat. No. 4,327,510 to Grantham. To load the sheet, an operator locates the corner portions of a sheet and drapes the sheet across two V-belts. The laundry article is then spread by a blade member which is mounted between the two V-belts for admission to an ironer. Although the foregoing machines do not require manual clamping of the corner portions of the sheets, they still require an operator to precisely load the sheet to obtain an accurate spreading of the sheet.
Thus, it is desirable to provide an apparatus which increases the speed at which a sheet can be loaded. More particularly, it is desirable to provide a machine which obviates the need for an operator to locate a corner portion or the side edge of a sheet. Moreover, it is desirable to provide a spreading mechanism which accurately spreads the sheet without requiring an operator to precisely load the sheet.